<h3>{{welcome}}</h3>
<h3>第一种模板语法</h3>
<ul>
    <template ngFor var-item [ngForOf]="items">
        <li>{{item}}</li>
    </template>
</ul>
<h3>第二种模板语法（语法糖而已）</h3>
<ul>
	<li *ngFor="#item of items">{{item}}</li>
</ul>
<input type="text" #newItemName>
<button on-click="addItem(newItemName.value)" newItemName.value=''>增加商品</button>